<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="https://unpkg.com/vue"></script>
    <script >
        window.onload=function() {


            Vue.component('my-component', {
                template: '<div>A custom component!</div>'
            })
            // 创建根实例
            var app4 = new Vue({
                el: '#example'
            })
        }
    </script>
</head>
<body>
<div id="example">
    <my-component></my-component>
</div>
</body>
</html>